If you are still working, go find one letter

If you are working past 65 and keeping your employer's health plan, there is one piece of paper worth finding today.

Your plan is required to tell you each year, in writing, whether its drug coverage counts as Creditable coverage — what this means. It usually arrives in the fall and it usually gets thrown out.

Keep it. Going 63 days or more without creditable drug coverage starts a Part D — what this means late enrollment penalty that is permanent once it begins, and that letter is how you prove you had coverage all along.

If you cannot find it, email HR and ask. It is a two-minute request and it is the highest-value thing you can do this month.